Editing Theodore II Laskaris (section)

===Expansion===

[[File:Durrës city wall.jpg|thumb|left|alt=Ruins of stone walls.|Ruins of the Byzantine [[Durrës Castle|fortification around Dyrrachium]] (now [[Durrës]] in Albania)]]

Theodore's war against Bulgaria brought about a  rapprochement between Epirus and Serbia. Michael&nbsp;II of Epirus made a formal alliance with [[Stefan Uroš&nbsp;I]], [[King of Serbia]] ({{reign|1243|1276}}). He also sent gifts to the Albanian chiefs who had acknowledged Nicaean suzerainty to gain their support. Theodore's daughter, Maria, and Michael&nbsp;II's son and heir, [[Nikephoros I Komnenos Doukas|Nikephoros]] ({{reign|1266/68|1296/98}}), had been engaged during Vatatzes' reign. After making peace with the Bulgarians, Theodore ordered Michael&nbsp;II to send Nikephoros to Thessalonica to wed Maria. Nikephoros was accompanied by his mother, [[Theodora Petraliphaina]]. Theodore took her into custody, only allowing her to return to Epirus after Michael&nbsp;II ceded [[Servia, Greece|Servia]] and [[Dyrrachium]] to him. The possession of the two towns secured the Nicaean control of the [[Via Egnatia]],{{#tag:ref|This ancient road connected Constantinople and the [[Adriatic]] coast across the Balkan Peninsula.{{sfn|Angelov|2019|p=135}}|group=note}} but Michael&nbsp;II remained hostile to Theodore.{{sfn|Treadgold|1997|p=730}}{{sfn|Fine|2009|p=160}}{{sfn|Angelov|2019|pp=166–167}}

Theodore received the [[papal legate]], Bishop Constantine of [[Diocese of Orvieto|Orvieto]], in Thessalonica. Their negotiations about the church union and a new [[ecumenical council]]—a general assembly of Orthodox and Catholic bishops—proved fruitless, because the legate's authorization to make concessions was limited and Theodore was unwilling to make theological concessions. He also preserved the right to convoke the Orthodox bishops to a synod to discuss the conditions of the union. Theodore maintained a correspondence with the Holy See, but he did not initiate new negotiations with it.{{sfn|Angelov|2019|pp=167}}

The Mongols invaded Asia Minor and defeated Kaykaus&nbsp;II on 14&nbsp;October 1256. Theodore hurried back to Anatolia to oversee the preparations for its defense. Kaykaus sought asylum in Nicaea and the Mongols installed his brother, [[Kilij Arslan&nbsp;IV]] ({{reign|1246/49|1266}}), as the new sultan of Rum. Theodore assembled his troops on the plains near [[Magnesia on the Maeander|Magnesia]]. The Mongol ruler of Persia, the [[Ilkhan]] [[Hülagü]] ({{reign|1256|1265}}), sent a delegation to Theodore to begin negotiations about Kaykaus' future. Hülegü agreed to withdraw his army from Rum and ordered the division of the sultanate between Kaykaus and Kilij Arslan in the spring of 1257. Before leaving for Rum, Kaykaus ceded four fortresses in the valley of the river [[Lycus (river of Phrygia)|Lycus]] to Nicaea in return for a contingent of 300 auxiliary troops.{{sfn|Korobeinikov|2017|pp=721–722}}{{sfn|Angelov|2019|pp=169–171}} His achievements made Theodore self-confident. He proudly stated that his empire included territories as far as Dyrrachium on the [[Adriatic Sea]] and [[Doğanyurt|Cape Karambis]] on the [[Black Sea]]. His success during the war against Bulgaria had convinced him he should recruit soldiers from among Anatolian peasants. In a letter to Blemmydes, he stated that the native "[[Names of the Greeks#Revival in the meaning of "Hellene"|Hellenes]]" were more reliable than foreign mercenaries.{{sfn|Angelov|2019|pp=172–174}}{{sfn|Kanellopoulos|Lekea|2007|p=68}}